/*
 * Copyright (c) 2012-2017 Red Hat, Inc.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Red Hat, Inc. - initial API and implementation
 */
package org.eclipse.che.ide.api.editor.partition;

import java.util.List;

/**
 * Defines the interface of a character scanner used by rules. Rules may request the next character
 * or ask the character scanner to unread the last read character.
 */
public interface CharacterScanner {

  /** The value returned when this scanner has read EOF. */
  public static final int EOF = -1;

  /**
   * Provides rules access to the legal line delimiters. The returned object may not be modified by
   * clients.
   *
   * @return the legal line delimiters
   */
  List<String> getLegalLineDelimiters();

  /**
   * Returns the column of the character scanner.
   *
   * @return the column of the character scanner
   */
  int getColumn();

  /**
   * Returns the next character or EOF if end of file has been reached
   *
   * @return the next character or EOF
   */
  int read();

  /** Rewinds the scanner before the last read character. */
  void unread();
}
